Methods of and apparatus for alternate-reverse twisting of indefinite lengths of strand material



3,373,550 mavansn TWISTING J. M. SYMONDS RATUS FOR ALTERNATE OFINDEFINITE LENGTHS OF s'rnmn MATERIAL Filed June 10, 1965 METHODS OF ANDAPPA March 19,1968

uvmvzm J. M. SYMONDS FLYNN, MARN 8 JANGARA THIS ATTORNEY United StatesPatent METHODS OF AND APPARATUS FOR ALTER- NATE-REVERSE TWISTING 0FINDEFINHTE LENGTHS 0F STRAND MATERIAL John'Martin Symonds,Williamsviile, N.Y., assignor to Western Electric Company, Incorporated,New York, N.Y., a corporation of New York Filed June 10, 1965, Ser. No.462,858 6 Claims. (CI. 5734) ABSTRACT on THE DISCLOSURE Impartingalternate-reverse twists to indefinite lengths of strand material, inparticular a plurality of electrical conductors, by feeding the strandmaterial axially into and out of a rotating accumulator which cooperateswith a non-rotating accumulator which creates an alternatingdifierential between the entrance and exit speeds of the strand materialinto and out of the rotating accumulator. By making the entrance speedof the strand material into the rotating accumulator alternately greaterand less than the exit speed from the rotating accumulator, a netalternate-reverse twist is imparted to the strand material.

This invention relates to methods of and apparatus for alternate-reversetwisting of indefinite lengths of strand material, and moreparticularly, to methods of and apparatus for alternate-reverse twistingof a plurality of electrical conductors.

The principle of operation of the present invention is related to theinternal twister principle employed by the inertial twister embodimentsfor twisting wire-like members disclosed in US. Patent No. 3,096,610,issued July 9, 1963, to the Western Electric Company, Inc., as as signeeof Tillman T. Bunch. Briefly stated, such inertial twister principle isthat if lengths of strand material are fed axially into one end of arotating drum, or drum-like structure, the material will be thrownoutwardly by centrifugal force against the Walls of the drum and a twistof one direction will be imparted to the material.

It has been discovered that if the lengths of strand material areremoved or discharged axially out of the opposite end of the rotatingdrum, or equivalent structure, a twist in the opposite direction isimparted to the strand material.

If the drum, or equivalent structure, is rotating at a uniform rate, andif the entrance and exit speeds of the strand material into and out ofthe drum are the same, the net effect on the strand material is zero,i.e., the number of twists of one direction imparted to the strandmaterial upon its entrance into the rotating drum is exactly equal tothe twist in the opposite direction imparted to the strand material uponits exit from the drum.

It has been further discovered that if an alternating differential iscreated between the entrance and exit speeds of the strand material intoand out of the rotating drum or equivalent structure, analternate-reverse twist is imparted to the strand material. Morespecifically, if the speed of the strand material exiting the rotatingdrum is less than the speed at which the strand material is entering thedrum, all of the twists imparted to the material upon its entry into therotating drum will be removed and a twist in the opposite direction willbe imparted to the strand material. When the speed of the strandmaterial leaving the rotating drum is greater than the speed of thestrand material entering the drum, not all of the twists imparted to thestrand material upon its entry into the drum will be removed, and aportion of such initially imparted twist will remain in the strandmaterial. This discovery is included in a copending patent applicationSer. No. 462,857 filed June 10, 1965 in the name of Everett J. Shaw asassignor to the Western Electric Company, Incorporated.

The use of an alternate-reverse twist, for example, in pairs ofelectrical conductors, rather than a continuous actual twist, provides amajor manufacturing advantage, namely, the need for rotating a conductorsupply or takeup device, both in general being quite massive, iseliminated.

Accordingly, it is an object of the present invention to provide new andimproved methods of and apparatus for alternate-reverse twisting ofindefinite lengths of strand material.

A further object of the present invention is to provide new and improvedmethods and apparatus for alternatereverse twisting of indefinitelengths of strand material utilizing a rotatable accumulator.

A further object of the present invention is to provide new and improvedmethods and apparatus for alternatereverse twisting of indefinitelengths of strand material utilizing a pair of accumulators one of whichis rotatable.

The present invention utilizes two accumulators to provide analternate-reverse twist in indefinite lengths of strand material. Theaccumulators are of the same general type as the accumulator 91 shown inFIG. 1 of US. Patent No. 2,971,709, issued Feb. 14, 1961, and thecutover tower 18 shown in FIG. 1 of US. Patent No. 2,973,912, issuedMar. 7, 1961. The operation of the accumulators of the present inventioninsofar as the storing of the strand material is concerned, issubstantially the same as the above-referred to devices.

One of the accumulators of the present invention, however, is mountedfor rotation and the other accumulator is mounted for operation in theusual manner of accumulator take-up operation. The length of therotatable accumulator is alternately increased and decreased to providean alternating differential between the speed of the strand materialleaving the rotatable accumulator and the speed of the strand materialentering the rotatable accumulator. This alternating speed differentialprovides, as described above, an alternate-reverse twist in the strandmaterial. The length of the other accumulator is alternately decreasedand increased to provide take-up tor the material as the length of therotatable accumulator is being alternately increased and decreased.

A more complete understanding of the present invention may be obtainedfrom the following detailed description when read in conjunction withthe appended drawings, in which:

FIG. 1 is a diagrammatical representation of apparatus for providingindefinite lengths of strand material with alternate-reverse twists inaccordance with the teachings of the present invention; and

FIG. 2 is a plan view of a portion of specific structure which may beutilized to practice the present invention; and 7 FIG. 3 is a sectionalview taken substantially along the line 33 in FIG. 2.

Referring now to the drawings, and in particular FIG. 1, there are showndiagrammatically a rotatable accumulator, indicated generally by thenumerical designation 10, a take-up accumulator, indicated generally bythe numerical designation 12, and a pair of constant speed tractor typecapstans 14 and 16, of the type well known in the capstan art.

The accumulator 10 includes two sets of sheaves 18 and 20. The sets ofsheaves are rotatable, as indicated by the arrow 22, and sheaves 20 aremovable longitudinally of the axis of rotation of accumulator 10, andmore significantly, with respect to sheaves 18.

The accumulator 12 includes two sets of sheaves 24 and 26. Sheaves 26are mounted for movement upwardly and downwardly with respect to sheaves24.

A pair of electrical conductors 28, to be provided withalternate-reverse twists, is fed forward from a supply, not shown, bythe capstan 14 into the accumulator 10. The conductors 28 are fed overand around the sheaves 18 and20 of accumulator and then forward over andaround the sheaves 24 and 26 of the accumulator 12. The capstan 16 thenfeeds the conductors 28 forward and onto a suitable take-up reel, notshown.

It will now be assumed that the capstans 14 and 16 are operating atsubstantially constant and identical speeds, that the conductors 28occupy the positions shown n FIG. 1 as described above, and thataccumulator 10 1s rotating at a uniform rate in the direction indicatedby the arrow 22.

As the conductors 28 are fed forward by the capstans 14 and 16 at alinear speed S1, and are received by the rotating accumulator 10, atwist of one direction will be imparted to the conductors. As theconductors are fed further forward, or discharged from, the rotatingaccumulator 10 at a linear speed S2, and onto the accumulator 12, atwist will be imparted to the conductors in the opposite direction. Atsuch times that sheaves are not being .ITIOVEd longitudinally withrespect to sheaves 18, the linear speed S1 of the conductors enteringthe rotating accumulator 10 will be equal to the linear speed S2 of theconductors leaving, or being discharged from, the rotating accumulatorand no resulting twist will be imparted to the conductors.

When the sheaves 20 are moving toward the sheaves 18, the linear speedS2 of the conductors 28 leaving the rotating accumulator 10 will begreater than the linear speed S1 of the conductors entering the rotatingaccumulator. At such time S2 is greater than S1, not all of the twistsimparted by the rotating accumulator 10 upon the entry of the conductorsinto the accumulator will be removed, and the twisted conductors will befed forward onto the take-up accumulator 12.

At such time the sheaves 20 are moving toward the sheaves 18 of therotating accumulator 10, the sheaves 26 of take-up accumulator 12 aremoving downwardly from sheaves 24 so as to take up and store asutficient quantity of the conductors 28 to permit the linear speed S1of the conductors leaving the take-up accumulator to remain constant.

When the sheaves 20 are moving away from the sheaves 18, the linearspeed S2 of the conductors exiting the rotating accumulator 10 will beless than the linear speed S1 of the conductors entering the rotatingaccumulator, and all of the twist imparted to the conductors upon theirreceipt by the rotating accumulator 10 will be removed and twist in theopposite direction will be imparted to the conductors.

At such time sheaves 20 are moving away from the sheaves 1-8 of therotatable accumulator 10, the sheaves 26 of take-up accumulator 12 aremoving upwardly toward the sheaves 24 so as to give up a portion of theconductors accumulated or stored on the accumulator 12, which in turnpermits the linear speed S1 of the conductors leaving the take-upaccumulator to remain constant.

By moving alternately the sheaves 20 toward and away from the sheaves18, an alternating differential is created between the linear speeds S1and S2 of the conductors 28, and an alternate-reverse twist imparted tothe conductors.

Since one set of sheaves in each accumulator has the ability to movewith respect to the associated set of sheaves, the accumulators may besaid to be elongatable.

An actual embodiment of a rotatable and elongatable accumulator 10,which may be used to practice the present invention, is shown in FIG. 2.The accumulator 10 includes pairs of stationary support members 32 and34 which support fixedly the outer races of bearings 36 and 38,respectively.

A pair of generally annular shaped members 40 and 42, are mounted forrotation by being suitably secured, such as by a press fit, to the innerraces of the bearings 36 and 38, respectively.

Extending between the rotatable annular members and 42, are a pluralityof rods 44. The ends of the rods are secured fixedly, such as bywelding, to the members 40 and 42 and, thus, the rods are mounted forrotation with the annular members 40 and 42.

A pair of block members 48 are secured fixedly, such as by welding, tothe rods 44 and support a shaft 49 which extends between the blockmembers. The shaft 49 supports the set of sheaves 18 for rotation aboutits own axis and also supports the sheaves 18 for rotation with theannular members 40 and 42.

Secured slidably along the rods 44 is an annular member 50 which isprovided with slightly oversized apertures 52 through which extend therods 44. A groove 54 is provided around the periphery of the annularmember 50 and a shaft 56 extends across the center aperture of theannular member.

The shaft 56 supports the set of sheaves 20 for rotation about theshaft, for rotation with the rods 44 and annular rings 40 and 42, andfor reciprocating longitudinal movement with respect to the set ofsheaves 18.

Support blocks 60 and 62 support rotatably a helical lead screw 64 whichincludes the helix 65. A gear 66 is secured fixedly to one end of thescrew and the gear through intermediate gear 68, is in engagement with apinion 70 provided on the drive shaft of a reversible motor 72.

Traveling block 76 encircles the helical lead screw 64, in engagementwith the helix 65 formed thereon, and is provided with a cylindricallyshaped pin 80 which resides within the peripheral groove 54 of annularmember 50. As reversible rotational motion, provided by the reversiblemotor 72, is transmitted to the helical lead screw by theafore-mentioned gearing, reciprocating translational motion is impartedto the traveling block 76 by the helix 65 of the helical lead screw.This motion is transmitted to the annular member 50 by the pin 80 of thetraveling block and reciprocating longitudinal motion is imparted to theannular member 50 and the set of sheaves 20.

Rotational motion is imparted to the accumulator 10 by a unidirectional,variable-speed motor 84. The motor shaft is provided with a pulley 86which is engaged by a belt 88 which belt is also in engagement with apulley 90 secured fixedly to the annular member 40. Thus, when rotativepower supplied by the motor 84 is transmitted to the pulley 40, theannular members 40 and 42, the rods 44 and the sheaves 18 and 20 andannular ring 50 supported, thereby, are rotated.

The cooperative engagement between the peripheral groove 50 and thecylindrical pin 80, permits the aforementioned reciprocatinglongitudinal movement to be imparted to the annular member 50 and set ofsheaves 20 while the sheaves and annular member are being rotated.

Accordingly, it will be appreciated that sets of sheaves 18 and 20 aremounted for rotational movement and that set of sheaves 20 is alsomounted for reciprocating longitudinal movement toward and away from setof sheaves 18.

In the practice of the present invention utilizing the structure of FIG.2, the pairs of electrical conductors 28 are fed forward by the capstans14 and 16, axially into the rotatable accumulator 10, over and aroundsets of sheaves 18 and 20, and axially out of the accumulator 10 onto atake-up accumulator 12 such as is shown diagrammatically in FIG. 1 andsuch as is shown and described in the patents referred to above. Theconductors 28 are passed over and around the sheaves 24 and 26 of thetake-up accumulator 12 and are then fed further forward by the capstansonto a suitable take-up reel, not shown.

The motor 84, as described above, imparts rotational motion to the setsof sheaves 18 and 20 and the reversible motor 72, as described above,imparts reciprocating longitudinal motion to the set of sheaves 20.

As the conductors 28 are received axially by the rotating accumulator10, a twist of one direction will be imparted to the conductors.

During the movement of the set of sheaves 20 toward the set of sheaves18, i.e., toward the leftward dashed outline position shown for sheaves20 in FIG. 2, the linear speed S2 of the conductors leaving or beingdischarged from the rotating accumulator will be greater than the linearspeed S1 of the conductors entering the rotating accumulator.

During the movement of the set of sheaves 29 away from the set ofsheaves 18, i.e., toward the rightward dashed outline position shown inFIG. 2, the linear speed S2 of the conductors leaving the rotatingaccumulator will be less than the linear speed S1 of the conductorsentering the rotating accumulator.

The alternating differential between the speeds S1 and S2, as describedabove, provides the conductors 28 with an alternate-reverse twist.

The number of alternate-reverse twists imparted per unit length of theconductors is dependent upon the rate of rotation of the rotatableaccumulator relative to the linear speed of the conductors, and, ofcourse, the rate of recipriocating translational movement of thetraveling block 76. Accordingly, the number of twists per unit lengthcan be varied by varying the speed of the motors '72 and 84 with respectto each other. This could be accomplished by varying solely the speed ofeither motor, or by varying the speeds of both motors as long as adifferent diiferential in motor speeds is established.

Although the present invention has been presented with reference toproviding indefinite lengths of strand material, viz., a pair ofelectrical conductors, with an alternate-reverse twist, it will beunderstood that the expression indefinite lengths of strand material isintended to include solid wires, stranded wires, tubing, ribbons and alltypes of members of relatively small cross section and of relativelyindefinite length.

It is manifest that many alterations and modifications can be made inthe present invention without departing from the spirit and scope of theinvention.

What is claimed is:

1. The method of providing indefinite lengths of strand material with analternate-reverse twist, which comprises the steps of:

feeding said material axially into and out of a rotating accumulator,and

varying the length of the accumulator to create an alternatingdifferential between the speed of the material entering the accumulatorand the speed of the material leaving the accumulator.

2. Apparatus for imparting an alternate-reverse twist to indefinitelengths of strand material, which comprises:

a rotatable and elongatable accumulator for receiving and imparting atwist of one direction to said material and for discharging andimparting a twist in the opposite direction to said material, and

means for varying the length of said accumulator to make the speed ofthe material discharged from said accumulator alternately faster andslower than the speed of the material received by the accumulator.

3. Apparatus for imparting an alternate-reverse twist to indefinitelengths of strand material, which comprises: a rotatable accumulator,including two sets of sheaves for axially receiving and discharging saidmaterial;

one of said set of sheaves being mounted for reciprocating movementlongitudinally of the axis of rotation of said accumulator;

means for imparting reciprocating movement to said one set of sheaves tocreate an alternating diiferential between the speed of the materialreceived by the accumulator and the speed of the material dischargedfrom the accumulator; and

a second accumulator for receiving the material discharged from saidrotatable accumulator and for providing take-up of said material as saidone set of sheaves is reciprocated.

4. Apparatus according to claim 3 for providing a variation in thenumber of alternate-reverse twists per unit length, which comprises:

means for varying the speed of rotation of said rotatable accumulator.

5. Apparatus for imparting an alternate-reverse twist to indefinitelengths of strand material, which comprises:

a rotatable accumulator, including two sets of sheaves,

for axially receiving and imparting a twist of one direction to saidmaterial and for discharging axially and imparting a twist to saidmaterial in a direction opposite to said one direction;

one of said set of sheaves being mounted for reciprocating movementlongitudinally of the axis of rotation of said accumulator;

means for imparting reciprocating movement to said one set of sheaves tomake the linear speed of the material discharged by said accumulatoralternately: (i) greater than the linear speed of the material receivedby said accumulator so as not to remove all of said imparted twist ofsaid one direction, and (ii) less than the linear speed of the materialreceived by said accumulator so as to remove all of said imparted twistof said one direction and to impart a twist to said material in adirection opposite to said one direction; and

an elongatable accumulator including two sets of sheaves, one of whichset is movable with respect to the other set, and for providing take-upfor said material during said reciprocation of said one set of sheaves.

6. Apparatus according to claim 5 for providing a variation in thenumber of alternate-reverse twists imparted per unit length, whichcomprises:

a variable speed motor for rotating said rotatable accumulator.

References Cited UNITED STATES PATENTS 2,837,292 6/1958 Adamson 242-4752,882,677 4/1959 Davey 57-156 2,971,709 2/1961 Ellis 24225 2,998,6949/1961 HaugWitZ 57-58.52 3,090,190 5/1963 Boussu et al 5777.3 X3,169,360 2/1965 Corrall et al. 5734 FOREIGN PATENTS 1,084,796 7/1960Germany. 1,032,350 6/1958 Germany.

FRANK I. COHEN, Primary Examiner. WERNER SCHROEDER, Assistant Examiner.

